Search results for "composite"
showing 10 items of 4584 documents
A nitroreductase and glutathione responsive nanoplatform for integration of gene delivery and near-infrared fluorescence imaging
2020
A novel platform rationally integrating indocyanine green analogues and an arginine-rich dendritic peptide with both nitroreductase (NTR) and glutathione (GSH) reduction responsive linkers was developed. This multifunctional platform can enable selective and efficient gene delivery and specific turn-on fluorescence imaging in tumors.
Gold(I)-catalysed cascade reactions in the synthesis of 2,3-fused indole derivatives.
2015
A gold(I)-catalysed hydroaminative/arylative cascade for the efficient synthesis of a variety of indole-fused skeletons has been developed. Factors controlling the catalyst loading required in these transformations involving 1,3-unsubstituted indole intermediates have been revealed, allowing isolation of an unprecedented 1,3-dimetallated 3H-indole gold complex characterized by X-ray diffraction.
Recycling of plastics from packaging
1997
Plastic waste coming from the separate collection of packaging film was recycled and characterized. The material is a blend of low density and linear low density polyethylene and after recycling shows mechanical and rheological properties depending on the processing conditions and apparatus. High processing temperature and high residence times strongly enhance the degradation processes and reduce the mechanical properties, in particular the elongation at break. A possible use of this recycled plastic is for the production of low pressure pipes but the properties are lower than those of virgin pipe grade polyethylene. By introducing additives, like antioxidants, inert fillers and impact modi…
Effect of fillers on the properties of recycled polymers
2003
The main problems in post-consumer plastics recycling are due to the degradation undergone during lifetime and during processing steps. Moreover, for heterogeneous recycling, the incompatibility among the different polymeric phases give rise to secondary materials with low mechanical and thermomechanical properties. The properties-reprocessing relationships are an important tool for determining not only the properties of the recycled polymers but also the strategies to apply (processing conditions, stabilisers, fillers, compatibilizers, etc) in order to obtain recycled polymers with good mechanical properties. In this work the effect of adding inert fillers and modifier agents to recycled p…
A two-component model for the 2260cm−1 infrared absorption band in electron irradiated amorphous SiO2
2011
Abstract We report an experimental study by infrared absorption (IR) measurements focused on the effects of electron irradiation in the dose range from 1.2 × 10 3 kGy to 5 × 10 6 kGy on the intrinsic band peaked at 2260 cm − 1 in amorphous silicon dioxide (a-SiO 2 ) materials. This IR band is particularly relevant as it is assigned to an overtone of the strong asymmetric stretching vibration of Si–O–Si bridges and consequently it is intimately related to the Si–O–Si bond angle distribution. In a recent work we have shown that structural modifications induced by irradiation take place through the nucleation of confined high-defective and densified regions statistically dispersed into the w…
Modelling pavement surface characteristics for noise prediction through Bailey-related indicators
2021
The aggregate gradation of bituminous mixtures (hot mix asphalts, HMA) is one of the major factors affecting their surface texture. In turn, this latter is a crucial factor and influences drivers and bystanders’ safety, comfort, and health. Despite this, the design of texture levels still lacks sound bases and dedicated algorithms and this negatively affects the acoustic design of bituminous mixtures. Consequently, the objectives of this study were confined into the derivation of relationships to be used in mix design to predict texture levels. Experimental data were analyzed, in the pursuit of setting up appropriate models and algorithms. Analyses involved the consideration of Bailey-relat…
Timing effect of intramyocardial hydrogel injection for positively impacting left ventricular remodeling after myocardial infarction
2015
Intramyocardial injection of various injectable hydrogel materials has shown benefit in positively impacting the course of left ventricular (LV) remodeling after myocardial infarction (MI). However, since LV remodeling is a complex, time dependent process, the most efficacious time of hydrogel injection is not clear. In this study, we injected a relatively stiff, thermoresponsive and bioabsorbable hydrogel in rat hearts at 3 different time points - immediately after MI (IM), 3 d post-MI (3D), and 2 w post-MI (2W), corresponding to the beginnings of the necrotic, fibrotic and chronic remodeling phases. The employed left anterior descending coronary artery ligation model showed expected infar…
The structural versatility of proton sponge bismuth halides
2022
Hybrid halometalates containing lead, tin, bismuth and antimony and organic cations have recently shown a bevy of interesting photophysical properties. Aiming at finding chemically stable and thermally inert species, three halobismutate species of this class, crystallized with proton sponge-derived cations (PRSH), have been isolated as microcrystalline powders by mixing 1,8-bis(dimethylamino)-naphthalene (proton sponge, or PRS) and bismuth oxide in concentrated HX acids (X = Cl, Br and I). The two isomorphous (PRSH)3Bi2X9 (X = Br, I) species, containing isolated [Bi2X9]3- anions, are triclinic at room temperature and convert upon heating into a monoclinic structure through a displacive …
Mechanical Behaviors of (As2S3)100-x(AgI)x Bulk Glasses and Thin Films
2012
Morphology evolution in mesoporous titania block copolymer composite films with increasing Sol-Gel reaction time
2013
A morphology evolution of thin films of titania from spherical mesopores to worm-shaped mesopores was realized by simply varying the sol–gel reaction time from 46 min to 25 h in the quadruple system consisting of polystyrene–block-poly(ethylene oxide) (PS–b-PEO), 1,4-dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP). Imaging techniques including scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to investigate the local structure change of the as-prepared, calcined, and UV-degraded composite films. Grazing incidence small angle X-ray scattering (GISAXS) experiments prove that the structure change in local areas is representative of that over the…